US20020124430A1 - Rotary particle-drying drum - Google Patents
Rotary particle-drying drum Download PDFInfo
- Publication number
- US20020124430A1 US20020124430A1 US10/093,075 US9307502A US2002124430A1 US 20020124430 A1 US20020124430 A1 US 20020124430A1 US 9307502 A US9307502 A US 9307502A US 2002124430 A1 US2002124430 A1 US 2002124430A1
- Authority
- US
- United States
- Prior art keywords
- baffles
- rotary particle
- particle dryer
- axis
- drum
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B11/00—Machines or apparatus for drying solid materials or objects with movement which is non-progressive
- F26B11/02—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles
- F26B11/04—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles rotating about a horizontal or slightly-inclined axis
- F26B11/0463—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles rotating about a horizontal or slightly-inclined axis having internal elements, e.g. which are being moved or rotated by means other than the rotating drum wall
- F26B11/0477—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles rotating about a horizontal or slightly-inclined axis having internal elements, e.g. which are being moved or rotated by means other than the rotating drum wall for mixing, stirring or conveying the materials to be dried, e.g. mounted to the wall, rotating with the drum
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B2210/00—Drying processes and machines for solid objects characterised by the specific requirements of the drying good
- F26B2210/16—Wood, e.g. lumber, timber
Definitions
- the present invention relates to a rotary particle-drying drum. More particularly this invention concerns such a drum used to dry wood chips for the production of oriented-strand board.
- German patent 3,345,118 of Otto Brudern describes a sugar-drying rotary drum having axially succeeding sets of outer axially extending baffles each having an outer edge secured to the drum, extending radially inward therefrom, and each forming an angularly open pocket.
- Axially succeeding sets of inner axially extending baffles each have an inner edge secured to a center shaft, extend radially outward therefrom, and each form an angularly open pocket directed angularly opposite to the outer pockets.
- Wood chips do not flow like sugar particles so such a rotary drum is not efficient at drying these types of particles. Dropping the particles through a substantial radial gap results in clumping and jamming. Furthermore the rigid interconnection of parts in this and similar systems causes considerable stresses when they are heated and expand. Thus the baffles can become loose as the fatigued joints where they are connected to the drum and shaft fail. Furthermore the known drums are not often sufficiently stiff with respect to torque so that, especially when heated, they can deform.
- Another object is the provision of such an improved rotary particle-drying drum which overcomes the above-given disadvantages, that is which is particularly effective at drying wood chips and that at the same time is of durable construction that can be counted on to have a long service life.
- the generally zig-zag shaped baffles are limitedly elastically deformable radially of the axis and can readily deform when heated without damage to the structure.
- the baffles are cascaded to make this even more effective, and also ensures that the material being dried flows from the outer baffles to the inner baffles for best possible drying.
- the baffles have a certain torsional rigidity so that the drum will not go far enough out of shape to be damaged. Securing the outer baffles to the inner baffles rather than to other structure in the drum reduces the likelihood of blocking the flow of particles, here normally chips for oriented-strand board, through the machine.
- At least some of the outer baffles have rear faces directed backward in the direction and provided with stiffening reinforcement.
- This reinforcement is respective radially and angularly extending bars fixed to the rear faces.
- outer baffles there is an even number of the outer baffles and there are half as many inner baffles as outer baffles.
- the outer baffles include long outer baffles and short outer baffles alternating with the long outer baffles.
- the inner baffles are radially generally aligned with the short outer baffles.
- FIGS. 2 and 3 are sections taken along respective lines II--II and III--III of FIG. 1.
- a drying drum has a pair of tubularly cylindrical parts 2 and 3 forming an inlet, a pair of similar parts 4 and 5 forming an outlet, a cylindrically tubular center part 1 between them of substantially larger radius R, and a center shaft 7 , all centered on a common axis 6 .
- the small-diameter end parts 2 and 5 have rings 33 and 34 by means of which they are supported in bearings on a base illustrated schematically at 35 for rotation of the assembly about the axis 6 in a direction 8 (FIGS. 2 and 3).
- Each set of baffles 36 and 36 ′ and 37 further has inner stabilizing rings 24 , coaxial outer stabilizing rings 31 , and struts 32 extending radially between them.
- the outer baffles 36 and 36 ′ have outer edges 9 welded to an inner face of the drum part 1 and the inner baffles 37 have inner edges 10 welded to the shaft 7 .
- each of the outer baffles 36 and 36 ′ has an overall radial dimension equal to between 40% and 60%, preferably 45% to 59% of the radius R.
- the baffles 36 and 36 ′ include long outer baffles 36 ′ which each form three pockets and which each have a radial dimension equal to 0.57R.
- Each long outer baffle 36 ′ has seven sections 11 , 12 , 13 , 14 , 15 , 16 , and 17 , the outer section 11 having the edge 9 secured to the drum part 1 .
- the first pocket formed by the sections 11 and 12 has an apex angle of 95° and the section 12 inclined 0° to a perpendicular from a radius from the axis 6 .
- the second pocket formed by the sections 13 and 14 has an apex angle of 88° and an inclination of the section 14 of ⁇ 12°
- the third pocket formed by the sections 15 and 16 has an apex angle of 83° and an inclination of ⁇ 23°.
- the sections 11 , 13 , and 15 each have a radial dimension of 0.15R and the sections 12 , 14 , and 16 respectively of 0.09R, 0.08R, and 0.08R.
- the last section 17 is inclined at ⁇ 25° and has a radial dimension of 0.09R.
- Axially extending ribs 26 form inward extensions of the sections 13 .
- the shorter baffles 36 have on their rear faces reinforcing strips or ribs 25 formed as metal bars welded in place. Axially extending ribs 27 project inward from the apexes of the sections 20 and 21 generally perpendicular to the sections 21 .
- the outer rings 24 are made of sheet metal and are provided at each axial end of each set of outer baffles 36 and 36 ′. They are fixed to the baffles 36 and 36 ′ and are spaced outward from the axis 6 by between 0.40R and 0.50R. Thus the rings engage the long baffles 36 ′ at the apexes of the innermost pockets formed by the sections 15 and 16 and the short baffles 36 just outward of the inner ends of their innermost sections 22 .
- each set one-half as many inner baffles 37 as outer baffles 36 and 36 ′, that is eight in the upstream three sets and nine in the downstream six sets.
- Each inner baffle 37 is generally radially aligned with a respective one of the short outer baffles 36 and each inner baffle extends outward from the axis 6 by a radial dimension of about 0.02R to 0.40R, here 0.31R.
- a gap equal to between 0.05R and 0.15R is left open between the outer ends of the inner baffles 37 and the inner ends of the long outer baffles 36 ′.
- the inner rings 31 are also made of sheet metal and are provided at each end of each set of baffles 37 . They are fixed to the baffles 37 and are space outward from the axis 6 by between 0.20R and 0.40R. In the upstream three baffle sets there are eight angularly equispaced and radially extending struts 32 extending between the rings 24 and 31 and in the downstream six baffle sets there are nine such struts 32 between each ring 24 and the respective ring 31 .
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Drying Of Solid Materials (AREA)
Abstract
Description
- The present invention relates to a rotary particle-drying drum. More particularly this invention concerns such a drum used to dry wood chips for the production of oriented-strand board.
- Commonly owned U.S. Pat. No. 6,119,363 described a rotary drying drum comprising a generally cylindrical outer wall centered on and rotatable about a horizontal axis and provided with axially rowed sets of axially extending baffles that extend radially inward from outer edges attached to the outer drum wall. These baffles are of zig-zag shape so as to form pockets and have inner ends that stop somewhat short of a central shaft extending through and carrying the drum. Each baffle has several sections extending at an angle of about 90° to one another and forming at least two angularly open pockets and the sets of baffles are set so the material cascades from the pockets of one set of baffles to the next as the drum rotates. Around twenty such baffles in each set extend to close to the center shaft at the axis of the drum. Struts extending from an inner ring stabilize the baffles.
- In order to dry wood chips between 5 mm and 50 mm wide and 75 mm to 175 mm long the drum has fewer, normally about twelve, baffles that have inner ends spaced somewhat farther out from the drum axis. No inner tube is used to dry these larger chips.
- As the drum diameter is increased to increase the capacity of the dryer, it becomes necessary to similarly increase the number of baffles. As a result their spacing at their radial inner ends can become quite small so it has been suggested to shorten some of the baffles in order to prevent clogging. Such shortening reduces the contact area and, thus, the efficiency of the dryer. Drums of large diameter, 5 m to 6 m, cannot have a properly dimensioned inner tube.
- German patent 3,345,118 of Otto Brudern describes a sugar-drying rotary drum having axially succeeding sets of outer axially extending baffles each having an outer edge secured to the drum, extending radially inward therefrom, and each forming an angularly open pocket. Axially succeeding sets of inner axially extending baffles each have an inner edge secured to a center shaft, extend radially outward therefrom, and each form an angularly open pocket directed angularly opposite to the outer pockets. Thus sugar fed in one end of the drum is poured from the outer pockets to the inner pockets across a considerable space between the inner edges of the outer baffles and the outer edges of the inner baffles.
- Wood chips do not flow like sugar particles so such a rotary drum is not efficient at drying these types of particles. Dropping the particles through a substantial radial gap results in clumping and jamming. Furthermore the rigid interconnection of parts in this and similar systems causes considerable stresses when they are heated and expand. Thus the baffles can become loose as the fatigued joints where they are connected to the drum and shaft fail. Furthermore the known drums are not often sufficiently stiff with respect to torque so that, especially when heated, they can deform.
- It is therefore an object of the present invention to provide an improved rotary particle-drying drum.
- Another object is the provision of such an improved rotary particle-drying drum which overcomes the above-given disadvantages, that is which is particularly effective at drying wood chips and that at the same time is of durable construction that can be counted on to have a long service life.
- A rotary particle dryer has according to the invention a shaft extending along an axis and a hollow drum coaxially and spacedly surrounding the shaft and rotatable about the axis in a direction. A set of axially extending inner baffles fixed to the shaft extend radially outward therefrom and each form at least one angularly open inner pocket. A set of axially extending outer baffles fixed to the drum extend radially inward therefrom and each form at least two angularly open outer pockets. In accordance with the invention structure mechanically connects the inner baffles directly with the outer baffles.
- Thus the generally zig-zag shaped baffles are limitedly elastically deformable radially of the axis and can readily deform when heated without damage to the structure. The baffles are cascaded to make this even more effective, and also ensures that the material being dried flows from the outer baffles to the inner baffles for best possible drying. On the other hand the baffles have a certain torsional rigidity so that the drum will not go far enough out of shape to be damaged. Securing the outer baffles to the inner baffles rather than to other structure in the drum reduces the likelihood of blocking the flow of particles, here normally chips for oriented-strand board, through the machine.
- The structure according to the invention includes an inner ring fixed to the inner baffles, an outer ring fixed to the outer baffles, and a plurality of struts extending radially between and fixed to the rings. Both of the rings are centered on the axis and the struts extend generally radially. Normally the struts and rings are made of sheet steel.
- At least some of the outer baffles have rear faces directed backward in the direction and provided with stiffening reinforcement. This reinforcement is respective radially and angularly extending bars fixed to the rear faces.
- Furthermore according to the invention the drum has a predetermined inner radius from the axis, and the inner baffles have a radial dimension equal to between 20% and 40% of the radius. Similarly the inner baffles have radial outer ends spaced from inner ends of the outer baffles by a radial distance equal to between 5% and 15% of the radius. Such dimensions are particularly effective with chips between 100 mm and 150 mm long and between 20 mm and 50 mm wide in a drum having a diameter of 5 m to 6 m.
- According to the invention there is an even number of the outer baffles and there are half as many inner baffles as outer baffles. The outer baffles include long outer baffles and short outer baffles alternating with the long outer baffles. The inner baffles are radially generally aligned with the short outer baffles.
- The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:
- FIG. 1 is a partly diagrammatic axial section taken along lines I--I of FIGS. 2 and 3; and
- FIGS. 2 and 3 are sections taken along respective lines II--II and III--III of FIG. 1.
- As seen in FIG. 1 a drying drum has a pair of tubularly
cylindrical parts 2 and 3 forming an inlet, a pair ofsimilar parts common axis 6. The small-diameter end parts 2 and 5 haverings axis 6 in a direction 8 (FIGS. 2 and 3). - The center drum part1 holds nine axially spaced sets of outer sheet-
metal baffles inner baffles 37 with thebaffles 36 alternating with thebaffles 36′. Relative to adirection 23 in which particles to be dried move through the drum, there are sixteenouter baffles inner baffles 37 in each of the upstream three sets and eighteenouter baffles 37 and nineinner baffles 37 in each of the downstream six sets. Each set ofbaffles baffles baffles 37. Each set ofbaffles rings 24, coaxial outer stabilizingrings 31, andstruts 32 extending radially between them. Theouter baffles inner baffles 37 haveinner edges 10 welded to the shaft 7. - More particularly, each of the
outer baffles baffles outer baffles 36′ which each form three pockets and which each have a radial dimension equal to 0.57R. Each longouter baffle 36′ has sevensections outer section 11 having the edge 9 secured to the drum part 1. The first pocket formed by thesections section 12 inclined 0° to a perpendicular from a radius from theaxis 6. The second pocket formed by thesections section 14 of −12°, and the third pocket formed by thesections sections sections last section 17 is inclined at −25° and has a radial dimension of 0.09R.Axially extending ribs 26 form inward extensions of thesections 13. - The shorter baffles36 each form two pockets and each have an overall radial dimension equal to 0.49R. Each
baffle 36 has fivesections outer section 18 having theedge 10 secured to the shaft 7. The first pocket formed by thesections sections sections ribs 25 formed as metal bars welded in place.Axially extending ribs 27 project inward from the apexes of thesections sections 21. - The outer rings24 are made of sheet metal and are provided at each axial end of each set of
outer baffles baffles axis 6 by between 0.40R and 0.50R. Thus the rings engage thelong baffles 36′ at the apexes of the innermost pockets formed by thesections short baffles 36 just outward of the inner ends of theirinnermost sections 22. - As mentioned above, there are in each set one-half as many
inner baffles 37 asouter baffles inner baffle 37 is generally radially aligned with a respective one of the shortouter baffles 36 and each inner baffle extends outward from theaxis 6 by a radial dimension of about 0.02R to 0.40R, here 0.31R. Thus a gap equal to between 0.05R and 0.15R is left open between the outer ends of theinner baffles 37 and the inner ends of the long outer baffles 36′. - Each
inner baffle 37 is formed of threesections inner sections first section 28 has a radial dimension of 0.15R and extends radially of theaxis 6. Themiddle section 29 has a radial dimension of 0.08R and forms with thefirst section 28 the angle of 118°. Theoutermost section 30 has a radial dimension of 0.06R and an inclination of −20°. - The inner rings31 are also made of sheet metal and are provided at each end of each set of
baffles 37. They are fixed to thebaffles 37 and are space outward from theaxis 6 by between 0.20R and 0.40R. In the upstream three baffle sets there are eight angularly equispaced and radially extendingstruts 32 extending between therings such struts 32 between eachring 24 and therespective ring 31. - Thus as the drum rotates in the direction8 the material captured in the forwardly open outer pockets of the
outer baffles respective baffles baffles inner baffles 37 which will spill out their contents as they move down into the vertical 6-o'clock position, and so on. This transfer between theouter baffles inner baffles 37 ensures good contacting of the material being dried and the hot air circulated axially through the drum.
Claims (13)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE10111613 | 2001-03-10 | ||
DE10111613.6 | 2001-03-10 | ||
DE10111613A DE10111613A1 (en) | 2001-03-10 | 2001-03-10 | Rotary drum for drying free-flowing goods |
Publications (2)
Publication Number | Publication Date |
---|---|
US20020124430A1 true US20020124430A1 (en) | 2002-09-12 |
US6718652B2 US6718652B2 (en) | 2004-04-13 |
Family
ID=7677022
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/093,075 Expired - Fee Related US6718652B2 (en) | 2001-03-10 | 2002-03-07 | Rotary particle-drying drum |
Country Status (3)
Country | Link |
---|---|
US (1) | US6718652B2 (en) |
CA (1) | CA2374378C (en) |
DE (1) | DE10111613A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150300738A1 (en) * | 2010-05-26 | 2015-10-22 | Astec, Inc. | Apparatus and method for tube dryer |
CN107763999A (en) * | 2017-12-08 | 2018-03-06 | 郑州市同鼎机械设备有限公司 | A kind of sand drier broken up thermal-arrest frame and thermal-arrest frame is broken up with this |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3713633A (en) * | 1971-10-07 | 1973-01-30 | J Falk | Rotary dryer |
US3950861A (en) * | 1974-11-29 | 1976-04-20 | Stearns-Roger Corporation | Rotary dryer for stringy material |
US4338732A (en) * | 1980-12-15 | 1982-07-13 | Allis-Chalmers Corporation | Lifter cage for asphalt plant, dryers and drum mixers |
US4628614A (en) * | 1983-09-26 | 1986-12-16 | Thompson Stanley P | Flighting for horizontal dryers |
US4894930A (en) * | 1987-04-01 | 1990-01-23 | Productization, Inc. | Rotary drum dryer with nonconducting nonstick surface |
CA2017953A1 (en) * | 1990-05-25 | 1991-11-25 | Richard L. Ronning | High density single pass heat exchanger for drying fragmented moisture bearing products |
DE19631998C1 (en) | 1996-08-08 | 1997-10-09 | Buettner Ges Fuer Trocknungs U | Rotary drum drying free-flowing material |
-
2001
- 2001-03-10 DE DE10111613A patent/DE10111613A1/en not_active Ceased
-
2002
- 2002-03-04 CA CA002374378A patent/CA2374378C/en not_active Expired - Fee Related
- 2002-03-07 US US10/093,075 patent/US6718652B2/en not_active Expired - Fee Related
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150300738A1 (en) * | 2010-05-26 | 2015-10-22 | Astec, Inc. | Apparatus and method for tube dryer |
CN107763999A (en) * | 2017-12-08 | 2018-03-06 | 郑州市同鼎机械设备有限公司 | A kind of sand drier broken up thermal-arrest frame and thermal-arrest frame is broken up with this |
Also Published As
Publication number | Publication date |
---|---|
US6718652B2 (en) | 2004-04-13 |
DE10111613A1 (en) | 2002-09-12 |
CA2374378A1 (en) | 2002-09-10 |
CA2374378C (en) | 2008-09-02 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: BUTTNER GESELLSCHAFT FUR TROCKNUNGS-UND UMWELLTTEC Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KLUG, ANDREAS;SCHRODER, WOLFGANG;REEL/FRAME:012917/0555 Effective date: 20020502 |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
AS | Assignment |
Owner name: BUETTNER ENERGIE- UND TROCKNUNGSTECHNIK GMBH, GERM Free format text: CHANGE OF NAME;ASSIGNOR:BUETTNER GESELLSCHAFT FUER TROCKNUNGS- UND UMWELTTECHNIK MBH;REEL/FRAME:028918/0574 Effective date: 20120302 |
|
REMI | Maintenance fee reminder mailed | ||
LAPS | Lapse for failure to pay maintenance fees | ||
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20160413 |